HMX – rear anti-roll bar

In my most recent post on the rear suspension rebuild, I neglected to mention the rear anti-roll bar. In addition to the stiffer rear springs, the Spirit AMX also received thicker anti-roll bars front and rear, which made things slightly more difficult. Ah, but how do you measure an anti-roll bar? With the method shown above: Start grabbing open-ended wrenches, and the one that slips neatly over the bar shows the diameter of the bar. So the AMX bar measures 3/4-inch.

While the Spirit GT bar that was under the car measured 5/8-inch.

Where it made things slightly more difficult was in finding the anti-roll bar bushings. No exact reproductions for the 3/4-inch bushings seem to exist, so I ordered some generic urethane bushings from Prothane. As it turns out, the Prothane brackets look like they will bolt to the stock bracket’s holes.

Mikel Smithsonsays:

July 23, 2009 12:42 pm

That’ interesting, I read an article once that stated that the Spirit GT was the best handling car that AMC ever built and I remembered this statement because of my sons 83 GT that we are finishing up. I am surprised to see that the Spirit AMX sway bar is larger…maybe it handled better than the GT ?

Daniel Strohlsays:

July 23, 2009 1:12 pm

@Mikel-
If you can recall where you read that, I’d like to see a copy!

I was surprised to see that the rear bar is larger, too, but the wrenches don’t lie. the most I’ve found so far on the topic from AMC was in the 1979 brochure, which said the rally-tuned suspension package (with “heavy-duty front and rear swaybars”) was optional in the GT and standard in the AMX, while the handling package (with “unique front sway bar” and “rear sway bar”) was optional on all Spirits except the Spirit GT and four-cylinder Spirits.

I should probably collect brochures from the remaining years of Spirit production to see if that changed at all after ’79.

July 23, 2009 4:06 pm

Daniel Strohlsays:

July 23, 2009 4:34 pm

Jeff Reevessays:

July 23, 2009 10:07 pm

Dan: the Prothane brackets will NOT fit the Spirit. Guess how I know?

You’ll have to reuse the stock front brackets and bolts. Stupid me threw away my old stock brackets thinking “I’ve got shiny new ones in the package with the bushings”. I had to go get another set off a junkyard Concord so they would actually fit the car.

Daniel Strohlsays:

July 24, 2009 7:46 am

Mikel Smithsonsays:

July 24, 2009 12:42 pm

Dan, I will look for that article as I collect all gremlin/hornet articles, toys and cars and run across spirit stuff all the time. I give the spirit articles to my son to add to his spirit collection so I figure that’s the place to look. I always remembered that comment because it gets a rise out of all the 2 seat AMX guys.
Mike

Iansays:

August 3, 2009 11:26 am

I used the prothane brackets on my spirit by drilling one new mounting hole per bracket. One of the holes was correct. For the second one I ran a bolt through the new hole I drilled an it all worked fine.

ig88bountyhntrsays:

August 21, 2009 1:10 pm

It took me a few minutes to figure out the wrench trick for measuring the bar. After I beat that hurdle, I had the same problem finding an exact repro. Do you have a part # or SKU for the bushings you ended up going with? I can’t make it out from the picture.